Gasulla Manel, Jordana Josep, Robert Francesc-Josep, Berenguer Jordi
e-CAT Reaserch Group, Department of Electronic Engineering, Castelldefels School of Telecommunications and Aerospace Engineering, Universitat Politècnica de Catalunya, c/Esteve Terradas, 7, 08860 Castelldefels (Barcelona), Spain.
CSC Research Group, Department of Signal Theory and Communications, Castelldefels School of Telecommunications and Aerospace Engineering, Universitat Politècnica de Catalunya, c/Esteve Terradas, 7, 08860 Castelldefels (Barcelona), Spain.
Sensors (Basel). 2017 Jul 25;17(8):1712. doi: 10.3390/s17081712.
Rectennas, which mainly consist of an antenna, matching network, and rectifier, are used to harvest radiofrequency energy in order to power tiny sensor nodes, e.g., the nodes of the Internet of Things. This paper demonstrates for the first time, the existence of an optimum voltage gain for high-pass L-matching networks used in rectennas by deriving an analytical expression. The optimum gain is that which leads to maximum power efficiency of the rectenna. Here, apart from the L-matching network, a Schottky single-diode rectifier was used for the rectenna, which was optimized at 868 MHz for a power range from -30 dBm to -10 dBm. As the theoretical expression depends on parameters not very well-known a priori, an accurate search of the optimum gain for each power level was performed via simulations. Experimental results show remarkable power efficiencies ranging from 16% at -30 dBm to 55% at -10 dBm, which are for almost all the tested power levels the highest published in the literature for similar designs.
整流天线主要由天线、匹配网络和整流器组成，用于收集射频能量，为微型传感器节点（如物联网节点）供电。本文首次通过推导解析表达式，证明了整流天线中使用的高通L型匹配网络存在最佳电压增益。最佳增益是使整流天线功率效率最大化的增益。这里，除了L型匹配网络，整流天线还使用了肖特基单二极管整流器，该整流器在868 MHz频率下针对-30 dBm至-10 dBm的功率范围进行了优化。由于理论表达式依赖于先验不太知名的参数，因此通过仿真对每个功率水平的最佳增益进行了精确搜索。实验结果表明，功率效率显著，在-30 dBm时为16%，在-10 dBm时为55%，几乎在所有测试功率水平下，这些都是文献中报道的类似设计的最高值。
